Triazolopyridine dyes and thermal transfer of methine dyes

ABSTRACT

Triazolopyridine dyes useful for thermal transfer of methine dyes have the formula ##STR1## where R 1  is C 1  -C 20  -alkyl, which may be substituted and interrupted by one or more oxygen atoms, or is substituted or unsubstituted phenyl or hydroxyl, 
     R 2  is a 5- or 6-membered carbocyclic or heterocyclic ring which may be substituted and benzofused, 
     R 3  is cyano, carbamoyl, carboxyl or C 1  -C 4  -alkoxycarbonyl, 
     R 4  is oxygen or a radical of the formula ##STR2##  where L 1  is in each case C 1  -C 6  -alkyl which may be interrupted by 1 or 2 oxygen atoms, and 
     X is CH or nitrogen.

The present invention relates to novel triazolopyridine dyes of theformula I ##STR3## where R¹ is C₁ -C₂₀ -alkyl, which may be substitutedand interrupted by one or more oxygen atoms, or is substituted orunsubstituted phenyl or hydroxyl,

R² is a 5- or 6-membered carbocyclic or heterocyclic ring which may besubstituted and benzo fused,

R³ is cyano, carbamoyl, carboxyl or C₁ -C₄ -alkoxycarbonyl,

R⁴ is oxygen or a radical of the formula ##STR4##

where L¹ is in each case C₁ -C₄ -alkyl which may be interrupted by 1 or2 oxygen atoms, and

X is CH or nitrogen,

and to a process for the thermal transfer of methine dyes.

U.S. Pat. No. A-4 769 360 discloses benzoquinoneimine dyes which arederived from p-phenylenediamine derivatives and are said to be suitablefor thermal transfer printing. However, it has been found that thesedyes have inadequate coloristic properties.

It is an object of the present invention to provide new dyes which areadvantageous for the thermal transfer process.

We have found that this object is achieved by the triazolopyridine dyesof the formula I defined at the beginning.

The dyes of the formula I can exist in multiple tautomeric forms whichare all encompassed by the claim. For example, compounds where R⁴ isoxygen can exist inter alia in the following tautomeric forms: ##STR5##

When R¹ in the formula I is substituted C₁ -C₂₀ -alkyl, possiblesubstituents are for example phenyl, C₁ -C₄ -alkylphenyl, C₁ -C₄-alkoxyphenyl, halophenyl, C₁ -C₈ -alkanoyloxy, C₁ -C₂₀ -alkoxycarbonyl,C₁ -C₂₀ -alkoxycarbonyloxy, the alkyl chains of the two last-mentionedradicals being optionally interrupted by from 1 to 4 oxygen atoms and/orphenyl- or phenoxy-substituted, halogen, hydroxyl and cyano.

When R¹ in the formula I is alkyl interrupted by oxygen atoms,preference is given to those alkyl radicals which are interrupted byfrom 1 to 4 oxygen atoms, in particular by 1 or 2 oxygen atoms.

When R¹ in the formula I is substituted phenyl, possible substituentsare for example C₁ -C₈ -alkyl, C₁ -C₈ -alkoxy, halogen, in particularchlorine or bromine, and carboxyl.

R² can be derived for example from the components of the benzene,indole, quinoline, aminonaphthalene, pyrrole, aminothiazole,benzimidazole, benzothiazole, aminothiophene or diaminopyridine series.

Important radicals R² are for example those of the formulae IIa to IIu##STR6## where n is 0 or 1,

L² and L³ are identical or different and each is independently of theother hydrogen or the abovementioned radical R¹,

R⁵ and R⁶ are identical or different and each is independently of theother hydrogen, hydroxyl, unsubstituted or phenyl- or C₁ -C₄-alkylphenyl-substituted C₁ -C₈ -alkyl, unsubstituted or phenyl- or C₁-C₄ -alkylphenyl-substituted C₁ -C₈ -alkoxy, C₁ -C₈ -alkanoylamino, C₂-C₈ -alkylsulfonylamino or C₁ -C₈ -monoalkylaminosulfonylamino or-dialkylaminosulfonylamino,

R⁷ is hydrogen or methyl,

R⁸ is hydrogen, halogen, C₁ -C₈ -alkyl, unsubstituted or C₁ -C₄ -alkyl-or C₁ -C₄ -alkoxy-substituted phenyl, unsubstituted or C₁ -C₄ -alkyl- orC₁ -C₄ -alkoxysubstituted benzyl, cyclohexyl, thienyl, hydroxyl or C₁-C₈ -monoalkylamino,

R⁹ is cyano, carbamoyl, C₁ -C₈ -monoalkylcarbamoyl or -dialkylcarbamoylor C₁ -C₈ -alkoxycarbonyl, and

R¹⁰ is halogen, hydrogen, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy, C₁ -C₄-alkylthio or unsubstituted or C₁ -C₄ -alkylsubstituted phenyl.

Any alkyl appearing in the abovementioned formulae is eitherstraight-chain or branched.

R¹, R⁵, R⁶, R⁸, R¹⁰, L¹ and L² are each for example methyl, ethyl,propyl, isopropyl, butyl, isobutyl, secbutyl or tert-butyl.

R¹, R⁵, R⁶, R⁸, L¹ and L² may each also be for example pentyl,isopentyl, neopentyl, tert-pentyl, hexyl, 2-methylpentyl, heptyl,1-ethylpentyl, octyl, 2-ethylhexyl or isooctyl.

R¹ may also be for example nonyl, isononyl, decyl, isodecyl, undecyl,dodecyl, tridecyl, isotridecyl, tetradecyl, pentadecyl, hexadecyl,heptadecyl, octadecyl, nonadecyl, eicosyl (the designations isooctyl,isononyl, isodecyl and isotridecyl are trivial names which are derivedfrom the alcohols obtained by the oxo process--cf. on this pointUllmanns Encyklopadie der technischen Chemie, 4th edition, volume 7,pages 215 to 217, and volume 11, pages 435 and 436).

R¹, L¹ and L² may each also be for example 2-methoxyethyl,2-ethoxyethyl, 2-propoxyethyl, 2-isopropoxyethyl, 2-butoxyethyl, 2- or3-methoxypropyl, 2- or 3-ethoxypropyl, 2- or 3-propoxypropyl, 2- or3-butoxypropyl, 2- or 4-methoxybutyl, 2- or 4-ethoxybutyl, 2- or4-propoxybutyl, 3,6-dioxaheptyl, 3,6-dioxaoctyl, 4,8-dioxanonyl,3,7-dioxaoctyl, 3,7-dioxanonyl, 4,7-dioxaoctyl, 4,7-dioxanonyl, 2- or4-butoxybutyl or 4,8-dioxadecyl.

R¹ may also be for example 3,6,9-trioxadecyl,3,6,9-trioxaundecy1,3,6,9,12-tetraoxatridecy1,3,6,9,12-tetraoxatetradecyl,2-carboxyethyl, 2-methoxycarbonylethyl, benzyl, 1- or 2-phenylethyl,3-benzyloxypropyl, phenoxymethyl, 6-phenoxy-4-oxahexyl,8-phenoxy-4-oxaoctyl, 2-, 3- or 4-chlorophenyl or 2-, 3- or4-carboxylphenyl.

R³ and R⁹ are each for example methoxycarbonyl, ethoxycarbonyl,propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonylor sec-butoxycarbonyl.

R⁹ may also be for example mono- or dimethylcarbamoyl, mono- ordiethylcarbamoyl, mono- or dipropylcarbamoyl, mono- ordiisopropylcarbamoyl, mono- or dibutylcarbamoyl orN-methyl-N-butylcarbamoyl.

R⁵, R⁶ and R¹⁰ may each also be for example methoxy, ethoxy, propoxy,isopropoxy, butoxy, isobutoxy or sec-butoxy.

R¹⁰ may also be for example methylthio, ethylthio, propylthio,isopropylthio, butylthio, isobutylthio or sec-butylthio.

R¹, R⁸ and R¹⁰ may each also be for example phenyl, 2-, 3- or4-methylphenyl, 2-, 3- or 4-ethylphenyl, 2-, 3- or 4-propylphenyl, 2-,3- or 4-isopropylphenyl, 2-, 3- or 4-butylphenyl or 2,4-dimethylphenyl.

R¹ and R⁸ may each also be for example 2-, 3- or 4-methoxyphenyl, 2-, 3-or 4-ethoxyphenyl, 2-, 3- or 4-isobutoxyphenyl or 2,4-dimethoxyphenyl.

R¹ may also be for example 2-cyanoethyl, 4-cyanobutyl, 2-hydroxyethyl,5-hydroxynonyl or a radical of the formula ##STR7##

Preference is given to triazolopyridine dyes of the formula I where R³is cyano.

Preference is also given to triazolopyridine dyes of the formula I whereR² is derived from a component of the benzene, indole, quinoline,aminonaphthalene, pyrrole, aminothiazole, benzimidazole, benzothiazole,aminothiophene or diaminopyridine series.

Preference is also given to triazolopyridine dyes of the formula I whereR¹ is C₁ -C₁₂ -alkyl, which may be substituted by C₁ -C₆ -alkanoyloxy,C₁ -C₈ -alkoxycarbonyl (whose alkyl chains may each be interrupted by 1or 2 oxygen atoms), phenyl or C₁ -C₄ -alkylphenyl and interrupted by 1or 2 oxygen atoms.

Particular preference is given to triazolopyridine dyes of the formula Iwhere R² is alkyl, alkoxyalkyl, alkanoyloxyalkyl or alkoxycarbonylalkyl,which may each have up to 12 carbon atoms, or is unsubstituted ormethyl-substituted benzyl or unsubstituted or methylsubstituted phenyl.

Particular preference is also given to triazolopyridine dyes of theformula I where R² is a radical of the abovementioned formula IIa, IIc,IIk, IIl, IIm or IIn, where

L² and L³ are each independently of the other alkyl,

alkoxyalkyl, alkanoyloxyalkyl or alkoxycarbonylalkyl, which may eachhave up to 12 carbon atoms, or hydrogen, unsubstituted ormethyl-substituted benzyl or unsubstituted or methyl-substituted phenyl,

R⁵ and R⁶ are each independently of the other hydrogen, C₁ -C₄ -alkyl,C₁ -C₄ -alkoxy or C₁ -C₈ -alkanoylamino, and

R⁸ is hydrogen, C₁ -C₄ -alkyl, unsubstituted or C₁ -C₄ -alkyl- or C₁ -C₄-alkoxy-substituted phenyl, benzyl or thienyl.

The dyes of the formula I according to the present invention can beprepared in a conventional manner.

For instance, those triazolopyridine dyes of the formula I where X is CHcan be obtained by condensing aldehydes of the formula III

    R.sup.2 --CHO                                              (III),

where R² is as defined above, with triazolopyridines of the formula IV##STR8## where R¹, R³ and R⁴ are each as defined above.

Those triazolopyridine dyes of the formula I where X is nitrogen can beobtained for example by condensing the nitroso compounds of the formulaV

TI R² --NO (V),

where R² is as defined above, or by oxidative coupling of the aminocompounds of the formula VI

    R.sup.2 --NH.sub.2                                         (VI),

where R² is as defined above, with the triazolopyridines IV.

The triazolopyridines of the formula IV are likewise compounds known perse. Their preparation is described for example in earlier German PatentApplication P 39 26 770.9.

It is a further object of the present invention to provide a process forthe thermal transfer of dyes, a process wherein the dyes used shouldideally have no application defects.

In the thermal transfer printing process, a transfer sheet whichcontains a thermally transferable dye in one or more binders, with orwithout suitable assistants, on a substrate is heated from the back withan energy source, for example a thermal printing head, in short heatingpulses (duration: fractions of a second), as a result of which the dyemigrates out of the transfer sheet and diffuses into the surface coatingof a receiving medium. The essential advantage of this process is thatthe amount of dye to be transferred (and hence the color gradation) iseasy to control by adjusting the energy supply to the heat source.

In general, color recording is carried out using the three subtractiveprimaries yellow, magenta and cyan (with or without black). To ensureoptimal color recording, the dyes must have the following properties:

ready thermal transferability,

little tendency to migrate within or out of the surface coating of thereceiving medium at room temperature,

high thermal and photochemical stability and also resistance to moistureand chemical substances,

suitable hues for subtractive color mixing,

a high molar absorption coefficient,

resistance to crystallization on storage of the transfer sheet,

ready industrial availability.

Experience shows that these requirements are very difficult to meet allat once.

For this reason most of the existing thermal transfer printing dyes fallshort of the postulated ideal.

We have found that the object is achieved, and that the transfer ofmethine dyes by diffusion from a transfer to plastic-coated paper withthe aid of an energy source is possible to advantageous effect, on usinga transfer on which there is or are situated one or more dyes of theformula I and/or Ia ##STR9## where R¹ is C₁ -C₂₀ -alkyl, which may besubstituted and interrupted by one or more oxygen atoms, or issubstituted or unsubstituted phenyl or hydroxyl,

R² is a 5- or 6-membered carbocyclic or heterocyclic ring which may besubstituted and benzo fused,

R³ is cyano, carbamoyl, carboxyl or C -C -alkoxycarbonyl,

R⁴ is oxygen or a radical of the formula ##STR10## where L¹ is in eachcase C₁ -C₈ -alkyl which may be interrupted by 1 or 2 oxygen atoms, and

X is CH or nitrogen.

A suitable energy source for the transfer of the dyes of the formula Iand/or Ia by diffusion is for example a thermal printing head or alaser. The use of a thermal printing head is preferred.

Preference is given to the process involving the transfer of dyes of theformula I.

Preference is further given to the process involving the transfer oftriazolopyridine dyes of the formula I where R³ is cyano.

Preference is further given to the process involving the transfer oftriazolopyridine dyes of the formula I where R² is derived from acomponent of the benzene, indole, quinoline, aminonaphthalene, pyrrole,aminothiazole, benzimidazole, benzothiazole, aminothiophene ordiaminopyridine series.

Preference is further given to the process involving the transfer oftriazolopyridine dyes of the formula I where R¹ is C₁ -C₁₂ -alkyl, whichmay be substituted by C₁ -C₆ -alkanoyloxy, C₁ -C₈ -alkoxycarbonyl (whosealkyl chains may each be interrupted by 1 or 2 oxygen atoms), phenyl orC₁ -C₄ -alkylphenyl and interrupted by 1 or 2 oxygen atoms.

Particular preference is given to the process involving the transfer oftriazolopyridine dyes of the formula I where R¹ is alkyl, alkoxyalkyl,alkanoyloxyalkyl or alkoxycarbonylalkyl, which may each have up to 12carbon atoms, or is unsubstituted or methyl-substituted benzyl orunsubstituted or methyl-substituted phenyl.

Particular preference is further given to the process involving thetransfer of triazolopyridine dyes of the formula I where R² is a radicalof the abovementioned formula IIa, IIc, IIk, IIl, IIm or IIn, where L²and L³ are each independently of the other alkyl, alkoxyalkyl,alkanoyloxyalkyl or alkoxycarbonylalkyl, which may each have up to 12carbon atoms, or hydrogen, unsubstituted or methyl-substituted benzyl orunsubstituted or methyl-substituted phenyl,

R⁵ and R⁶ are each independently of the other hydrogen, C₁ -C₄ -alkyl,C₁ -C₄ -alkoxy or C₁ -C₈ -alkanoylamino, and

R⁸ is hydrogen, C₁ -C₄ -alkyl, unsubstituted or C₁ -C₄ -alkyl- or C₁ -C₄-alkoxy-substituted phenyl, benzyl or thienyl.

To prepare the transfer required for the process, the dyes areincorporated into suitable organic solvents, e.g. chlorobenzene,isobutanol, methyl ethyl ketone, methylene chloride, toluene,tetrahydrofuran or a mixture thereof, together with one or more bindersand with or without the addition of other auxiliaries, to form aprinting ink. It preferably contains the dye in a molecularly dispersed,i.e. dissolved, form. The printing ink is applied to the inert substrateby knife coating and the coating is dried in air. A suitable binder isany resin or polymer material which is soluble in organic solvents andcapable of binding the dye to the inert substrate in such a way that itwill not rub off. Preference here is given to those binders which, afterthe printing ink has dried in air, hold the dye in the form of a clear,transparent film without visible crystallization of the dye.

Examples of such binders are cellulose derivatives, eg. methylcellulose,ethylcellulose, ethylhydroxyethylcellulose, hydroxypropylcellulose,cellulose acetate or cellulose acetobutyrate, starch, alginates, allylresins, vinyl resins, polyvinyl alcohol, polyvinyl acetate, polyvinylbutyrate and polyvinylpyrrolidones. It is also possible to use polymersand copolymers of acrylates or derivatives thereof, such as polyacrylicacid, polymethyl methacrylate or styrene-acrylate copolymers, polyesterresins, polyamide resins, polyurethane resins or natural CH resins, suchas gum arabic. Other suitable binders are described for example inDE-A-3 524 519.

The preferred binders are ethylcellulose, ethylhydroxyethylcellulose,polyvinyl butyrate and polyvinyl acetate.

The ratio of binder to dye is preferably within the range from 1:1 to5:1 by weight.

Suitable assistants are for example release agents as described inEP-A-227 092, EP-A-192 435 and the patent applications cited therein andalso in particular organic additives which stop the transfer dye fromcrystallizing in the course of storage or heating of the inked ribbon,for example cholesterol or vanillin.

Inert substrates are for example tissue, blotting or parchment paper orplastics films of high heat stability, for example uncoated ormetal-coated polyester, polyamide or polyimide. The inert substrate mayadditionally be coated on the side facing the energy source with alubricant, or slipping, layer in order to prevent adhesion of the energysource to the substrate material. Suitable lubricants are described forexample in EP-A-216 483 and EP-A-227 095. The thickness of the substrateis in general from 3 to 30 μm, preferably from 5 to 10 μm.

Suitable dye receiver layers are basically all temperature stableplastic layers having an affinity for the dyes to be transferred andpreferably glass transition temperatures (T^(g)) within the range 50°C.<Tg<100° C., e.g. modified polycarbonates and polyesters. Suitablerecipes for the receiver layer composition are described in detail forexample in EP-A-227 094, EP-A-133 012, EP-A-133 011, EP-A-111 004,JP-A-199 997/1986, JP-A-283 595/1986, JP-A-237 694/1986 and JP-A-127392/1986.

Transfer is preferably effected, as described above, by means of athermal printing head which must be heatable to ≧300° C. for dyetransfer to take place within the time interval t: 0<t<15 msec. Onheating, the dye migrates out of the transfer sheet and diffuses intothe surface coating of the receiving medium.

Compared with the dyes used in existing processes, the novel dyestransferred in the process according to the present invention are ingeneral notable for improved migration properties in the receivingmedium at room temperature, readier thermal transferability, readierindustrial availability, better resistance to moisture and chemicalsubstances, higher color strength, better solubility, higher thermal andphotochemical stability and in particular better purity of hue.

The purity of hue results from the steeper slope of the main absorptionband and from the higher transparency in blue and green regions.

The novel dyes give complete coverage of the range from red toturquoise. Of particular interest here are magenta and cyan dyes which,owing to their remarkable brilliance, are suitable as primaries forsubtractive color mixing.

Details concerning the preparation are given in the examples, in whichpercentages are by weight, unless otherwise stated.

The examples which follow illustrate the invention.

Preparation of the Dyes ##STR11##

11 g of N,N-dibutyl-m-toluidine were nitrosated with sodium nitrite at0° C. to 5° C. in aqueous hydrochloric acid. After 2 hours the mixturewas rendered alkaline with 25% strength ammonia at 0°-10° C. andextracted with 150 ml of methylene chloride. The organic phase was thenadded with stirring to a suspension of 13.6 g of the compound of theformula ##STR12## in acetic anhydride at room temperature. The reactionbegan immediately to give a slightly exothermic response (32° C.). Themixture was subsequently stirred at room temperature for a further 2hours, heated to 40° C. and admixed with water to hydrolyse the aceticanhydride. The organic phase was extracted three times with water in aseparating funnel and concentrated in a rotary evaporator. The residuewas suspended in water, the suspension was neutralized with bicarbonatesolution and filtered with suction, and the filter residue was washeduntil neutral and dried at room temperature.

Yield: 23.3 g=92% of theory

Melting point: 147° C. λ_(max) (THF): 615 nm

R_(f) : 0.60 (8:2 toluene/ethyl acetate).

Example P1 was also followed to prepare the following dyes by in eachcase distilling off all the methylene chloride and carrying out thereaction at 120° C.

    __________________________________________________________________________     ##STR13##                Yield: Melting point: λ.sub.max (THF):                                 R.sub.f :                                                                             41% of theory ≈175° C.                                         614 nm 0.36 (8:2 toluene/ethyl acetate)     __________________________________________________________________________

EXAMPLE P3

    __________________________________________________________________________     ##STR14##              Yield: λ.sub.max (THF): R.sub.f :                                             36% of theory 611 nm 0.38                                                     (8:2 toluene/ethyl acetate)                    __________________________________________________________________________

EXAMPLE P4

    __________________________________________________________________________     ##STR15##              Yield: Melting point: λ.sub.max (THF):                                 R.sub.f :                                                                             29% of theory ≈180° C. 610                                     nm 0.29 (8:2 toluene/ethyl acetate)           __________________________________________________________________________

EXAMPLE p5

    __________________________________________________________________________     ##STR16##                     Yield: λ.sub.max (THF): R.sub.f                                               30% of theory 626 nm 0.36 (ethyl                                              acetate)                                __________________________________________________________________________

EXAMPLE P6 ##STR17## 8.3 g of 2-morpholino-5-formylthiazole and 13.6 gof the compound of the formula ##STR18## were dissolved in 100 ml ofmethylene chloride. After 100 ml of acetic anhydride had been added, themethylene chloride was distilled off and the temperature was increasedto 120° C. After cooling to 100° C. with stirring, the target productprecipitated. Following addition of 100 ml of methanol, the mixture wasstirred overnight and filtered with suction, and the filter residue waswashed with methanol and dried.

Yield: 17.1 g=76% of theory

Melting point: >210° C.

λ_(max) (THF): 531 nm

R_(f) : 0.45 (ethyl acetate)

Example P6 was also followed to synthesize the following dyes:

EXAMPLE P7

    __________________________________________________________________________     ##STR19##            Yield: Melting point: λ.sub.max (THF):                                 R.sub.f :                                                                             93% of theory ≈143° C. 576                                     nm 0.26 (8:2 (toluene/ethyl acetate)            __________________________________________________________________________

EXAMPLE P8

    __________________________________________________________________________     ##STR20##                  Yield: Melting point: λ.sub.max (THF):                                 .sub.f :                                                                              85% of theory ≈188° C.                                         32 nm 0.69 (ethyl acetate)                __________________________________________________________________________

EXAMPLE P9

    __________________________________________________________________________     ##STR21##            Yield: Melting point: Sublimation: λ.sub.max                           (THF): R.sub.f :                                                                      64% of theory ≈205° C.                                         200° C. 556 nm 0.21 (8:2 ethyl                                         acetate)                                        __________________________________________________________________________

EXAMPLE P10

    __________________________________________________________________________     ##STR22##             Yield: Melting point: λ.sub.max                                                31% of theory ≈218° C. 547                                     nm                                             __________________________________________________________________________

EXAMPLE P11

    __________________________________________________________________________     ##STR23##               Yield: Melting point: λ.sub.max                                                19% of theory ≈200° C.                                         536 nm                                       __________________________________________________________________________     *) Examples P10 and P11 were each carried out using a moist mixture of

EXAMPLE P12

    __________________________________________________________________________     ##STR24##                  Yield: Melting point: Sublimation: λ.su                                b.max (THF):                                                                          55% of theory ≈225° C.                                         14° C. 528 nm                      __________________________________________________________________________

Transfer of the Dyes

To be able to test the transfer characteristics of the dyes in aquantitative and simple manner, the heat transfer process was carriedout with large hotplates instead of a thermal printing head, thetransfer hotplates instead of a thermal printing head, the transfertemperature being varied within the range 70° C.<T<120° C. and thetransfer time being set at 2 minutes.

A) General recipe for coating the substrates with dye 1 g of binder weredissolved in 8 ml (8:2 v/v) of toluene/ethanol at from 40° to 50° C. Asolution of 0.25 g of dye with or without assistants in 5 ml oftetrahydrofuran was added by stirring. The print paste thus obtained wasapplied with an 80 μm knife to a sheet of polyester film (thickness:6-10 μm) and dried with a hairdrier.

B) Testing of thermal transferability

The dyes used were tested in the following manner: The polyester sheetdonor containing the dye under test in the coated front was placed facedown on a sheet of commercial Hitachi Color Video Print Paper (receiver)and pressed down. Donor/receiver were then wrapped in aluminum foil andheated between two hot plates at different temperatures T (within thetemperature range 70° C.<T<120° C.). The amount of dye diffusing intothe bright plastic layer of the receiver is proportional to the opticaldensity (=absorbance A). The latter was determined photometrically. Ifthe logarithm of the absorbance A of the colored receiver papersmeasured within the temperature range from 80° C. to 110° C. is plottedagainst the corresponding reciprocal of the absolute temperature, theresult is a straight line whose slope gives the activation energy ΔE_(T)for the transfer experiment: ##EQU1##

To complete the characterization, it is additionally possible to inferfrom the plots the temperature T*[° C] at which the absorbance A of thecolored receiver papers attains the value 1.

The dyes listed in the tables which follow were processed according toA), and the resulting dye-coated substrates were tested in respect oftheir transfer characteristics according to B). The tables list in someinstances the thermal transfer parameters T* and ΔE_(T), the absorptionmaxima of the dyes λ_(max) (measured in methylene chloride, unlessotherwise stated) and the binders used. The weight ratio of dye:binderis always 1:4. In those cases where an assistant is present, the weightratio of dye:assistant is 1:0.75.

The following abbreviations apply:

B=binder (EC=ethylcellulose, EHEC=ethylhydroxyethylcellulose,AC=cellulose acetobutyrate, M=mixture of polyvinyl butyrate andethylcellulose in a weight ratio of 2:1)

A assistant (chol=cholesterol).

                                      TABLE 1                                     __________________________________________________________________________     ##STR25##                                                                     Ex. Nr.                                                                            A.sup.1                                                                           A.sup.2                                                                             A.sup.3  X   A.sup.4   λ[nm]                                                                      B    A   T* [°C.]                                                                    ##STR26##            __________________________________________________________________________    1    CH.sub.3                                                                          CH(CH.sub.3).sub.2                                                                  H        N                                                                                  ##STR27##                                                                              610 M    --  108  15                    2    C.sub.2 H.sub.5                                                                   C.sub.6 H.sub.13                                                                    H        N                                                                                  ##STR28##                                                                              610 M    --  89   15                    3    C.sub.4 H.sub.9                                                                   C.sub.4 H.sub.9                                                                     CH.sub.3 N                                                                                  ##STR29##                                                                              623 M    --  90   17                    4    C.sub.2 H.sub.5                                                                   C.sub.4 H.sub.9                                                                     CH.sub.3 N                                                                                  ##STR30##                                                                              621 M    --  89   16                    5    C.sub.4 H.sub.9                                                                   C.sub.4 H.sub.9                                                                     CH.sub.3 N                                                                                  ##STR31##                                                                              621 M    --  91   16                    6    C.sub.4 H.sub.9                                                                   C.sub.2 H.sub.4 CN                                                                  H        N                                                                                  ##STR32##                                                                              590 M    --  111  14                    7    C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                     NHCOCH.sub.3                                                                           N                                                                                  ##STR33##                                                                              619 M    --  87   19                    8    C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                     NHCOCH.sub.3                                                                           N                                                                                  ##STR34##                                                                              619 M    --  89   18                    9    C.sub.2 H.sub.5                                                                   C.sub.4 H.sub.9                                                                     NHCOCH.sub.3                                                                           N   C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.4                                     H.sub.9   620 EHEC --  93   18                    10   C.sub.4 H.sub.9                                                                   C.sub.4 H.sub.9                                                                     NHCOCH.sub.3                                                                           N                                                                                  ##STR35##                                                                              623 M    --  110  15                    11   C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                     NHSO.sub.2 N(CH.sub.3).sub.2                                                           N                                                                                  ##STR36##                                                                              618 M    --  90   14                    12   C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                     H        CH                                                                                 ##STR37##                                                                              559 M    --  89   11                    13   CH.sub.3                                                                          CH.sub.3                                                                            H        CH                                                                                 ##STR38##                                                                              554 M    --  112  16                    14   C.sub.4 H.sub.9                                                                   C.sub.2 H.sub.5                                                                     OCH.sub.3                                                                              CH                                                                                 ##STR39##    AC   Chol                                                                              87   13                    15   C.sub.4 H.sub.9                                                                   C.sub.2 H.sub.5                                                                     OCH.sub.3                                                                              N   C.sub.4 H.sub.8 OC.sub.3 H.sub.7                                                            EC   --  92   16                    __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________     ##STR40##                                                                     Ex. Nr.                                                                            A.sup.1                                                                              A.sup.2                                                                             A.sup.3           X   λ[nm]                                                                      B  A  T* [°C.]                                                                     ##STR41##            __________________________________________________________________________    16   C.sub.2 H.sub.5                                                                      C.sub.4 H.sub.9                                                                     C.sub.6 H.sub.5   N   612 M  -- 86    16                    17   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5   N   615 M  -- 82    16                    18   CH(CH.sub.3).sub.2                                                                   CH(CH.sub.3).sub.2                                                                  C.sub.6 H.sub.5   N   617 M  -- 90    17                    19   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                      ##STR42##        N   624 M  -- 90    13                    20   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                      ##STR43##        N   621 M  -- 92    12                    21   C.sub.2 H.sub.5                                                                      C.sub.4 H.sub.9                                                                      ##STR44##        N   612 M  -- 84    17                    22   C.sub.2 H.sub.5                                                                      C.sub.4 H.sub.9                                                                      ##STR45##        N   611 M  -- 85    16                    23   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5   CH  560 M  -- 85    12                    24   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                     Thien-2-yl        CH  579 M  -- 90    16                    25   Benzyl CH.sub.3                                                                            H                 CH  537 M  -- 88     8                    26   C.sub.4 H.sub.9                                                                      C.sub.2 H.sub.5                                                                     C.sub.6 H.sub.5   CH  561 M  -- 90    12                    27   C.sub.2 H.sub.5                                                                      C.sub.2 H.sub.5                                                                      ##STR46##        CH  566 M  -- 109   10                    __________________________________________________________________________

                                      TABLE 3                                     __________________________________________________________________________     ##STR47##                                                                     Ex. No.                                                                            A.sup.1                                                                              A.sup.3                                                                             X  A.sup.4   λ[nm]                                                                      B  A  T* [°C.]                                                                    ##STR48##                      __________________________________________________________________________    28   C.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                     H     N                                                                                 ##STR49##                                                                              631 M  -- 110  24                              29   C.sub.6 H.sub.13                                                                     H     N                                                                                 ##STR50##                                                                              636 EC Chol                                                                             107  22                              30   C.sub.3 H.sub.7                                                                      CH.sub.3                                                                            N  C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.4 H.sub.9                                       640 EC -- 100  16                              31   C.sub.2 H.sub.5                                                                      H     CH                                                                                ##STR51##                                                                              --  M  --  98  15                              32   C.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                     CH.sub.3                                                                            CH                                                                                ##STR52##                                                                              --  EC -- 100  16                              33   H      NHCOCH.sub.3                                                                        N                                                                                 ##STR53##                                                                              616 M  --  98  14                              __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________     ##STR54##                                                                     Ex. No.                                                                            A.sup.1                                                                          A.sup.2                                                                             A.sup.3                                                                             X  λ[nm]                                                                      B  A  T* [°C.]                                                                    ##STR55##                              __________________________________________________________________________    34   H  CH(CH.sub.3).sub.2                                                                  CH(CH.sub.3).sub.2                                                                  N  608 N  -- 101  16                                      35   C.sub.2 H.sub.5                                                                  C.sub.3 H.sub.6 OCH.sub. 3                                                          C.sub.3 H.sub.6 OCH.sub.3                                                           N  619 N  --  94  17                                      __________________________________________________________________________

                  TABLE 5                                                         ______________________________________                                         ##STR56##                                                                     No.Ex.                                                                             Y      A.sup.3                                                                              X    λ[nm]                                                                        B    A   [°C.]T*                                                                     ##STR57##                        ______________________________________                                        36   CH.sub.2                                                                             C.sub.6 H.sub.5                                                                      N    616   M    --  90   14                                37   O      C.sub.6 H.sub. 5                                                                     N    612   M    --  92   15                                38   O      H      CH   537   M    --  87   13                                ______________________________________                                    

                                      TABLE 6                                     __________________________________________________________________________     ##STR58##                                                                     Ex. No.                                                                            A.sup.1                                                                          A.sup.2                                                                          A.sup.3                                                                             X  A.sup.4       λ[nm]                                                                      B  A  T* [°C.]                                                                    ##STR59##                   __________________________________________________________________________    39   C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  NHCOCH.sub.3                                                                        N                                                                                 ##STR60##    593 EC -- 129  15                           40   C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  NHCOCH.sub.3                                                                        N                                                                                 ##STR61##    593 EC -- 121  13                           41   C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  OCH.sub.3                                                                           N                                                                                 ##STR62##    570 EC -- 127  10                           42   C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  OCH.sub.3                                                                           N                                                                                 ##STR63##    570 EC -- 117  10                           43   C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                  H     CH C.sub.6 H.sub.13                                                                            528 M  --  78  14                           __________________________________________________________________________

                                      TABLE 7                                     __________________________________________________________________________     ##STR64##                                                                     No.Ex.                                                                           A.sup.1                                                                           A.sup.2   A.sup.3    X  A.sup.4                                                                              λ[nm]                                                                      B  A  [°C.]T*                                                                   ##STR65##                 __________________________________________________________________________    44 C.sub.3 H.sub.7                                                                   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                             2-Thienyl  N  C.sub.2 H.sub.4 OCH.sub.3                                                            626*                                                                              EC -- 100                                                                              14                         45 C.sub.2 H.sub.5                                                                   (C.sub.2 H.sub. 4 O).sub.2 C.sub.2 H.sub.5                                              C.sub.6 H.sub.5                                                                          N  C.sub.3 H.sub.6 OC.sub.2 H.sub.5                                                     584*                                                                              M  -- 94 13                         46 C.sub.3 H.sub.7                                                                   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                             2-Thienyl  N  C.sub.3 H.sub.6 OCH.sub.3                                                            624*                                                                              M  -- 98 12                         47 C.sub.2 H.sub.5                                                                   (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                               C.sub.6 H.sub.5                                                                          N  C.sub.2 H.sub.4 OCH.sub.3                                                            584*                                                                              EC -- 94 14                         48 C.sub.2 H.sub.5                                                                   (C.sub.2 H.sub.4 O).sub.3 C.sub.2 H.sub.5                                               C.sub.6 H.sub.5                                                                          N  C.sub.3 H.sub.6 OCH.sub.3                                                            584*                                                                              M  -- 96 13                         49 C.sub.2 H.sub.5                                                                   CH.sub.2 (C.sub.2 H.sub.4 O).sub.2 CH.sub.3                                             C.sub.6 H.sub.5                                                                          N  C.sub.2 H.sub.4 OCH.sub.3                                                            585*                                                                              M  -- 97 14                         50 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                         C.sub.6 H.sub.5                                                                          CH C.sub.2 H.sub.4 OCH.sub.3                                                            534 M  -- 91 13                         51 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                          ##STR66## CH C.sub. 6 H.sub.13                                                                    537 M  -- 84 18                         52 C.sub.2 H.sub.5                                                                   C.sub.2 H.sub.5                                                                         Thien-2-y  CH C.sub.6 H.sub.13                                                                     551 M  -- 88 19                         __________________________________________________________________________     *λ.sub.max was measured in THF                                    

                  TABLE 8                                                         ______________________________________                                         ##STR67##                                                                     No.Ex.                                                                               λ[nm]                                                                            B     A      [°C.]T*                                                                     ##STR68##                                 ______________________________________                                        53     590       M     --     99   12                                         ______________________________________                                    

Similar results are obtained with the dyes listed in Table 9. (The romannumerals under D refer to the abovementioned radicals of the formulaII).

                                      TABLE 9                                     __________________________________________________________________________     ##STR69##                                                                    Ex.-                                                                          No.                                                                              D  X  L.sup.2 R.sup.1    L.sup.3                                                                             R.sup.5                                                                              R.sup.6                                                                              Hue                           __________________________________________________________________________    54 IIa                                                                              CH C.sub.4 H.sub.9                                                                        ##STR70## C.sub.2 H.sub.5                                                                     H      H      Magenta violet                55 IIa                                                                              CH C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.5                                                                          C.sub.3 H.sub.7                                                                     H      H      Magenta                                                                       violet                        56 IIa                                                                              CH C.sub.2 H.sub.4 CO.sub.2 C.sub.2 H.sub.5                                              C.sub.4 H.sub.8 OCH.sub.3                                                                C.sub.2 H.sub.5                                                                     H      H      Magenta                       57 IIa                                                                              CH C.sub.2 H.sub.5                                                                       C.sub.3 H.sub.6 OC.sub.4 H.sub.9                                                         C.sub.2 H.sub.5                                                                     H      CH.sub.3                                                                             Magenta                                                                       violet                        58 IIa                                                                              CH CH(CH.sub.3).sub.2                                                                     ##STR71## CH(CH.sub.3).sub.2                                                                  H      OCH.sub.3                                                                            Magenta violet                59 IIa                                                                              CH C.sub.4 H.sub.9                                                                        ##STR72## C.sub.2 H.sub.5                                                                     H      CH.sub.3                                                                             Magenta violet                60 IIa                                                                              CH C.sub.4 H.sub.9                                                                       C.sub.7 H.sub.15                                                                         C.sub.2 H.sub.5                                                                     H      NHCOCH.sub.3                                                                         Magenta                                                                       violet                        61 IIa                                                                              CH C.sub.3 H.sub.7                                                                       (CH.sub.2).sub.2 CO.sub.2 C.sub.4 H.sub.9                                                C.sub.3 H.sub.6 OCH.sub.3                                                           H      H      Magenta                       62 IIa                                                                              N  C.sub.4 H.sub.9                                                                       (CH.sub.2).sub.2 CO.sub.2 C.sub.4 H.sub.9                                                C.sub.4 H.sub.9                                                                     H      H      Cyan                          63 IIa                                                                              N  C.sub.2 H.sub.5                                                                       C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OCH.sub.3                                               C.sub.2 H.sub.5                                                                     H      C.sub.2 H.sub.5                                                                      Cyan                          64 IIa                                                                              N  C.sub.2 H.sub.5                                                                        ##STR73## C.sub.3 H.sub.7                                                                     H      CH.sub.3                                                                             Cyan                          65 IIa                                                                              N  CH(CH.sub.3).sub.2                                                                    (CH.sub.2).sub.4 OC.sub.3 H.sub.7                                                        C.sub.2 H.sub.5                                                                     H      C.sub.2 H.sub.5                                                                      Cyan                          66 IIa                                                                              N  C.sub.4 H.sub.9                                                                        ##STR74## C.sub.2 H.sub.5                                                                     H      NHCOCH.sub.3                                                                         Cyan                          67 IIa                                                                              N  C.sub.3 H.sub.7                                                                        ##STR75## C.sub.2 H.sub.5                                                                     H      NHSO.sub.2 C.sub.4 H.sub.9                                                           Cyan                          68 IIa                                                                              N  C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                         C.sub.7 H.sub.15                                                                    H      NHSO.sub.2 C.sub.2 H.sub.5                                                           Cyan                          69 IIa                                                                              N  H                                                                                      ##STR76## C.sub.4 H.sub.9                                                                     OCH.sub.3                                                                            CH.sub.3                                                                             Cyan                          70 IIa                                                                              N  C.sub.2 H.sub.4 CN                                                                    (CH.sub.2).sub.2 OC.sub.6 H.sub.13                                                       C.sub.4 H.sub.9                                                                     H      CH.sub.3                                                                             Cyan                          71 IIa                                                                              N  H                                                                                      ##STR77## C.sub.5 H.sub.11                                                                    OC.sub.2 H.sub.5                                                                     CH.sub.3                                                                             Cyan                          72 IIb                                                                              CH C.sub.2 H.sub.5                                                                        ##STR78## --    --     H      Magenta violet                __________________________________________________________________________    Ex.-                                                                          No.                                                                              D  X  L.sup.2 R.sup.1    L.sup.4                                                                             R.sup.6                                                                              R.sup.5                                                                              Hue                           __________________________________________________________________________    73 IIb                                                                              CH C.sub.4 H.sub.9                                                                       (CH.sub.2).sub.4 OC.sub.4 H.sub.9                                                        --    --     H      violet                        74 IIb                                                                              N  C.sub.2 H.sub.5                                                                        ##STR79## --    --     H      Cyan                          75 IIc                                                                              CH C.sub.4 H.sub.9                                                                       (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                --    --     H      Magenta                                                                       violet                        76 IIc                                                                              CH C.sub.3 H.sub.6 OC.sub.4 H.sub.9                                                       ##STR80## --    --     H      Magenta violet                77 IIc                                                                              CH C.sub.2 H.sub.5                                                                       (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                --    --     H      Magenta                                                                       violet                        78 IIc                                                                              CH C.sub.2 H.sub.5                                                                       C.sub. 3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.6 H.sub.5                                       --    --     CH.sub.3                                                                             violet                        79 IIc                                                                              CH C.sub.4 H.sub.9                                                                       (CH.sub.2).sub.2 CO.sub.2 C.sub.5 H.sub.11                                               --    --     OCH.sub.3                                                                            violet                        80 IIc                                                                              CH C.sub.2 H.sub.5                                                                       (CH.sub.2).sub.2 OC.sub.5 H.sub.11                                                       --    --     C.sub.2 H.sub.5                                                                      violet                        81 IIc                                                                              CH C.sub.2 H.sub.4 CN                                                                    (CH.sub.2).sub.2 OC.sub.5 H.sub.11                                                       --    --     H      Magenta                       82 IIc                                                                              CH C.sub.2 H.sub.4 OH                                                                    (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                --    --     CH.sub.3                                                                             Magenta                       83 IIc                                                                              CH C.sub.2 H.sub.4 CO.sub.2 C.sub.2 H.sub.5                                              (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                --    --     H      Magenta                       84 IIc                                                                              N  (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                              ##STR81## --    --     H      Cyan                          85 IIc                                                                              N  C.sub.2 H.sub.5                                                                       (CH.sub.2).sub.4 OC.sub.3 H.sub.6 OC.sub.2 H.sub.5                                       --    --     CH.sub.3                                                                             Cyan                                                                          Turquoise                     86 IIc                                                                              N  C.sub.4 H.sub.9                                                                       CH.sub.3   --    --     H      Cyan                          87 IIc                                                                              N  H       C.sub.4 H.sub.8 OC.sub.3 H.sub.6 OC.sub.4 H.sub.9                                        --    --     CH.sub.3                                                                             Cyan                          88 IIc                                                                              N  C.sub.3 H.sub.7                                                                        ##STR82## --    --     NHCOCH.sub.3                                                                         Cyan Turquoise                89 IIc                                                                              N  C.sub.2 H.sub.4 CN                                                                    C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.4 H.sub.9                                        --    --     CH.sub.3                                                                             Cyan                          90 IIc                                                                              N  C.sub.3 H.sub.6                                                                       (C.sub.2 H.sub.4 O).sub.2 C.sub.4 H.sub.9                                                --    --     H      Cyan                          91 IIc                                                                              N  C.sub.2 H.sub.5                                                                       C.sub.2 H.sub.4 CO.sub.2 C.sub.7 H.sub.15                                                --    --     CH.sub.3                                                                             Cyan                                                                          Turquoise                     92 IIc                                                                              N  C.sub.2 H.sub.4 OH                                                                    C.sub.3 H.sub.6 OC.sub.3 H.sub.6 OC.sub.2 H.sub.5                                        --    --     H      Cyan                          93 IId                                                                              CH --                                                                                     ##STR83## --    H      H      Yellow                        94 IId                                                                              CH --      C.sub.3 H.sub.6 OC.sub.4 H.sub.9                                                         --    m-CH.sub.3                                                                           OC.sub.2 H.sub.5                                                                     Yellow                        95 IId                                                                              CH --                                                                                     ##STR84## --    m-CO.sub.2 C.sub.6 H.sub.13                                                          H      Yellow                        __________________________________________________________________________     ##STR85##                                                                    Ex.-                                                                          No.                                                                              D  X  L.sup.2 R.sup.1    L.sup.3                                                                             R.sup.6                                                                              R.sup.5                                                                              Hue                           __________________________________________________________________________    96 IIe                                                                              CH C.sub.3 H.sub.6 OC.sub.4 H.sub.9                                                       ##STR86## --    --     CH.sub.3                                                                             Magenta violet                97 IIe                                                                              N  C.sub.3 H.sub.7                                                                        ##STR87## --    --     H      Cyan Turquoise                98 IIe                                                                              N                                                                                 ##STR88##                                                                             ##STR89## --    --     CH.sub.3                                                                             Turquoise                     99 IIg                                                                              CH --                                                                                     ##STR90## --    --     H      Magenta violet                100                                                                              IIg                                                                              CH --      C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.6 H.sub.5                                        --    --     CH.sub.3                                                                             violet                        101                                                                              IIg                                                                              N  --      C.sub.3 H.sub.6 OC.sub.2 H.sub.4 OC.sub.4 H.sub.9                                        --    --     H      Cyan                          102                                                                              IIg                                                                              N  --                                                                                     ##STR91## --    --     CH.sub.3                                                                             Cyan Turquiose                103                                                                              IIg                                                                              N  --      C.sub.3 H.sub.6 OC.sub.3 H.sub.7                                                         --    --     NHCOCH.sub.3                                                                         Cyan                                                                          Turquiose                     __________________________________________________________________________

                                      TABLE 10                                    __________________________________________________________________________     ##STR92##                                                                     Ex.- No.                                                                         A.sup.1    A.sup.2                                                                               A.sup.3   X  A.sup.4                                                                              λ[mm]                                                                      B   A                                                                               T*[°C.]                                                                    ##STR93##            __________________________________________________________________________    104                                                                              CH(CH.sub.3).sub.2                                                                       C.sub.2 H.sub.5                                                                       CH.sub.3  N                                                                                 ##STR94##                                                                           621 EHEC                                                                              --                                                                              96  12                    105                                                                              C.sub.3 H.sub.7                                                                          C.sub.2 H.sub.5                                                                       CH.sub.3  N                                                                                 ##STR95##                                                                           621 EHEC                                                                              --                                                                              111 14                    106                                                                              C.sub.4 H.sub.9                                                                          C.sub.4 H.sub.9                                                                       NHCOC.sub.3 H.sub.7                                                                     N                                                                                 ##STR96##                                                                           625 EHEC                                                                              --                                                                              105 10                    107                                                                               ##STR97## C.sub.2 H.sub.5                                                                       H         CH                                                                                ##STR98##                                                                           555 EHEC                                                                              --                                                                              100  9                    108                                                                              C.sub.2 H.sub.4 OCOCH.sub.2 OCH.sub.3                                                    C.sub.2 H.sub.5                                                                       H         N                                                                                 ##STR99##                                                                           601 M   --                                                                               87 10                    109                                                                              C.sub.2 H.sub.4 Cl                                                                       C.sub.2 H.sub.5                                                                       H         N                                                                                 ##STR100##                                                                          595 M   --                                                                              84   9                    110                                                                              C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                                                       NHCO.sub.2 C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                             N                                                                                 ##STR101##                                                                          616 M   --                                                                              76  10                    111                                                                               ##STR102##                                                                              C.sub.2 H.sub.5                                                                       H         N                                                                                 ##STR103##                                                                          604 M   --                                                                              76   8                    112                                                                              C.sub.2 H.sub.4 OCOCH.sub.3                                                              C.sub.2 H.sub.5                                                                       H         N                                                                                 ##STR104##                                                                          604 EHEC                                                                              --                                                                              104 10                    113                                                                               ##STR105##                                                                              C.sub.2 H.sub.5                                                                       CH.sub.3  N                                                                                 ##STR106##                                                                          618 M   --                                                                              78  10                    114                                                                              C.sub.4 H.sub.9                                                                          C.sub.2 H.sub.5                                                                       CH.sub.3  N                                                                                 ##STR107##                                                                          618 M   --                                                                              94  11                    115                                                                              C.sub.4 H.sub.9                                                                          C.sub.4 H.sub.9                                                                       CH.sub.3  N                                                                                 ##STR108##                                                                          621 M   --                                                                              94  11                    116                                                                               ##STR109##                                                                              C.sub.2 H.sub.5                                                                       CH.sub.3  N                                                                                 ##STR110##                                                                          618 M   --                                                                              80   8                    117                                                                              C.sub.4 H.sub.9                                                                          C.sub.4 H.sub.9                                                                       H         N  C.sub.3 H.sub.7                                                                      616 M   --                                                                              73   7                    118                                                                              C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                                                       OCH(CH.sub.3).sub.2                                                                     N                                                                                 ##STR111##                                                                          601 M   --                                                                              82   9                    119                                                                              CH.sub.3   CH.sub.3                                                                              H         CH                                                                                ##STR112##                                                                          554 M   --                                                                              112 16                    120                                                                              C.sub.2 H.sub.4 OC.sub.4 H.sub.9                                                         C.sub.2 H.sub.5                                                                       H         N                                                                                 ##STR113##                                                                          615 M   --                                                                              109 11                    121                                                                              C.sub.2 H.sub.4 CN                                                                       C.sub.4 H.sub.9                                                                       H         N                                                                                 ##STR114##                                                                          590 M   --                                                                              111 13                    122                                                                              C.sub.4 H.sub.9                                                                          C.sub.4 H.sub.9                                                                       H         N                                                                                 ##STR115##                                                                          620 M   --                                                                              110 12                    123                                                                              C.sub.4 H.sub.9                                                                          C.sub.2 H.sub.5                                                                       CH.sub.3  N                                                                                 ##STR116##                                                                          621 M   --                                                                              117 16                    124                                                                              C.sub.4 H.sub.9                                                                          C.sub.2 H.sub.5                                                                       CH.sub.3  N  CH.sub.3                                                                             619 M   --                                                                              85   9                    125                                                                              C.sub.4 H.sub.9                                                                          C.sub.4 H.sub.9                                                                       CH.sub.3  N  C.sub.2 H.sub.5                                                                      619 M   --                                                                              83  10                    126                                                                              C.sub.4 H.sub.9                                                                          C.sub.2 H.sub.5                                                                       CH.sub.3  N  C.sub.2 H.sub.5                                                                      621 M   --                                                                              119 13                    127                                                                              C.sub.4 H.sub.9                                                                          C.sub.4 H.sub.9                                                                       CH.sub.3  N                                                                                 ##STR117##                                                                          625 M   --                                                                              88  12                    128                                                                              C.sub.4 H.sub.9                                                                          C.sub.4 H.sub.9                                                                       CH.sub.3  N  CH.sub.3                                                                             621 M   --                                                                              108 10                    129                                                                              C.sub.4 H.sub.9                                                                          CH.sub.3                                                                              H         N                                                                                 ##STR118##                                                                          607 M   --                                                                              82   9                    130                                                                              C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                                                       CH.sub.3  N                                                                                 ##STR119##                                                                          615 M   --                                                                              83  11                    131                                                                              (CH.sub.2).sub.2 CH(CH.sub.3).sub.2                                                      C.sub.2 H.sub.5                                                                       CH.sub.3  N                                                                                 ##STR120##                                                                          620 EHEC                                                                              --                                                                              92  13                    132                                                                              C.sub.2 H.sub.4 CH(CH.sub.3).sub.2                                                       C.sub.2 H.sub.5                                                                       CH.sub.3  N  C(CH.sub.3).sub.3                                                                    621 M   --                                                                              102  8                    133                                                                              CH.sub.2 CH(CH.sub.3).sub.2                                                              C.sub.4 H.sub.9                                                                       H         N  C(CH.sub.3).sub.3                                                                    615 M   --                                                                              83  11                    134                                                                              C.sub.4 H.sub.9                                                                          C.sub.4 H.sub.9                                                                       OCH.sub.3 N                                                                                 ##STR121##                                                                          603 M   --                                                                              98   6                    135                                                                              C.sub.2 H.sub.4 OCONHC.sub.4 H.sub.9                                                     C.sub.2 H.sub.5                                                                       H         N                                                                                 ##STR122##                                                                          596 M   --                                                                              97  16                    136                                                                              C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                                                       H         N                                                                                 ##STR123##                                                                          608 M   --                                                                              97  14                    137                                                                              C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                                                       NHCOCH.sub.2 OCH.sub.3                                                                  N                                                                                 ##STR124##                                                                          622 M   --                                                                              93   8                    138                                                                              C.sub.2 H.sub.4 OC.sub.2 H.sub.5                                                         C.sub.2 H.sub.5                                                                       NHCOCH.sub.3                                                                            N                                                                                 ##STR125##                                                                          623 M   --                                                                              88   8                    139                                                                              C.sub.2 H.sub.5                                                                          C.sub.2 H.sub.5                                                                        ##STR126##                                                                             N                                                                                 ##STR127##                                                                          624 M   --                                                                              81   8                    140                                                                              C.sub.2 H.sub.4 O.sub.2 CCH.sub.3                                                        C.sub.2 H.sub.4 O.sub.2 CH.sub.3                                                      NHCOCH.sub.2 OCH.sub.3                                                                  N                                                                                 ##STR128##                                                                          615 M   --                                                                              82   8                    141                                                                              C.sub.2 H.sub.4 O.sub.2 CC.sub.5                                                         C.sub.2 H.sub.4 O.sub.2 CC.sub.2 H.sub.5                                              NHCOC.sub.2 H.sub.5                                                                     N                                                                                 ##STR129##                                                                          616 M   --                                                                              83  10                    __________________________________________________________________________

                                      TABLE 11                                    __________________________________________________________________________     ##STR130##                                                                    No.Ex.                                                                           A.sup.1                                                                          A.sup.2                                                                          A.sup.3            X  A.sup.4                                                                             λ[mm]                                                                      B                                                                               A                                                                                T*[°C.]                                                                   ##STR131##                  __________________________________________________________________________    142                                                                              C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   ##STR132##        CH                                                                                ##STR133##                                                                         563 M --                                                                              155  3                           143                                                                              C.sub.2 H.sub.5                                                                  C.sub.2 H.sub.5                                                                   ##STR134##        N                                                                                 ##STR135##                                                                         623 M --                                                                              101 10                           __________________________________________________________________________

                                      TABLE 12                                    __________________________________________________________________________     ##STR136##                                                                   Ex.                                                                           No.                                                                              D  X  L.sup.2                                                                          R.sup.1                                                                             L.sup.3                                                                          Y    R.sup.5                                                                         R.sup.6                                                                         R.sup.8                                                                             λ.sub.max (nm)                     __________________________________________________________________________    144                                                                              IIa                                                                              N  CH.sub.3                                                                          ##STR137##                                                                         CH.sub.3                                                                         CO.sub.2 C.sub.4 H.sub.9                                                           H H --    680                                       145                                                                              IIa                                                                              CH C.sub.2 H.sub.5                                                                   ##STR138##                                                                         C.sub.4 H.sub.9                                                                  CO.sub.2 C.sub.4 H.sub.9                                                           H H --    638                                       146                                                                              IIk                                                                              CH C.sub.2 H.sub.5                                                                   ##STR139##                                                                         C.sub.2 H.sub.5                                                                  CN   --                                                                              --                                                                              C.sub.6 H.sub.5                                                                     636                                       147                                                                              IIk                                                                              CH C.sub.2 H.sub.5                                                                   ##STR140##                                                                         C.sub.2 H.sub.5                                                                  CN   --                                                                              --                                                                               ##STR141##                                                                         620                                       __________________________________________________________________________

We claim:
 1. A triazolopyridine dye of the formula I ##STR142## where R¹is C₁ -C₂₀ -alkyl, which may be substituted and interrupted by one ormore oxygen atoms, or is substituted or unsubstituted phenyl orhydroxyl,R² is a 5- or 6-membered carbocyclic or heterocyclic ring whichmay be substituted and benzo fused, R³ is cyano, carbamoyl, carboxyl orC₁ -C₄ -alkoxycarbonyl, R⁴ is oxygen or a radical of the formula##STR143## where L¹ is in each case C₁ -C₈ -alkyl which may beinterrupted by 1 or 2 oxygen atoms, and X is CH or nitrogen.
 2. Atriazolopyridine data as claimed in claim 1, wherein R³ is cyano.
 3. Atriazolopyridine dye as claimed in claim 1, wherein R² is selected fromthe group consisting of benzene, indole, quinoline, aminonaphthalene,pyrrole, aminothiazole, benzimidazole, benzthiazole, aminothiophene ordiaminopyridine series.
 4. A triazolopyridine dye as claimed in claim 1,wherein R¹ is C₁ -C₁₂ -alkyl, which may be substituted by C₁ -C₆-alkanoyloxy, C₁ -C₈ -alkoxycarbonyl (whose alkyl chains may each beinterrupted by 1 or 2 oxygen atoms), phenyl or C₁ -C₄ -alkylphenyl andinterrupted by 1 or 2 oxygen atoms.